A Rare Case of Extensive Oral Involvement in Bullous Systemic Lupus Erythematosus: Diagnostic and Therapeutic Challenges.

Bullous systemic lupus erythematosus (BSLE) is a rare autoantibody-mediated subepidermal blistering disease that affects fewer than 5% of systemic lupus erythematosus (SLE) patients. While oral involvement is generally mild, extensive oral lesions as the predominant manifestation are exceptionally uncommon and present significant diagnostic and therapeutic challenges. This report describes a unique case of BSLE with dominant and extensive oral involvement, a presentation rarely documented in the literature. A 29-year-old female presented to the Oral Medicine Clinic with severe, diffuse oral ulcerations of one week's duration (VAS pain score 8/10), which impaired swallowing and were accompanied by fever, without any history of new medication or food exposure. A 29-year-old female presented to the Oral Medicine Clinic with severe diffuse oral ulcerations for one week (VAS pain score 8/10) that impaired swallowing and were accompanied by fever, without any history of new medications or food exposure. Clinical examination identified widespread erythematous bullae and erosions across the oral mucosa, as well as non-scrapable white plaques on the dorsum and lateral tongue. Histopathological analysis revealed subepidermal separation with predominant neutrophilic infiltration, confirming BSLE and distinguishing it from other vesiculobullous disorders in the absence of direct immunofluorescence (DIF) testing. Management consisted of a multimodal approach, including topical therapy (dexamethasone ointment, antiseptic rinses, saline compresses, and protective emollients) and systemic therapy with high-dose intravenous methylprednisolone and oral cyclosporine, supported by antibiotics and analgesics under dermatology supervision. Notably, all oral lesions resolved completely within four weeks without the need for more aggressive systemic treatment. This case highlights the diagnostic value of a multidisciplinary, clinicopathological approach in confirming BSLE with dominant oral involvement, even when advanced immunofluorescence testing is unavailable, and demonstrates the effectiveness of a tailored, minimally invasive therapeutic strategy that achieved complete healing without the need for aggressive systemic therapy.